(1) Field of the Invention
This invention relates to an alkylation method for the preparation of diarylalkanes using a synthetic porous crystalline catalyst.
(2) Prior Art
Several methods have been proposed to react styrenes with aromatic compounds in the presence of zeolite catalysts to produce diarylalkanes, especially 1,1-diarylethane.
For example, disclosed in U.S. Pat. No. 5,073,655 is a method to alkylate benzene or the like with an alkylating agent such as styrene in the presence of a synthetic zeolite catalyst, called as MCM-22 which is characterized by an X-ray diffraction pattern.
Furthermore, in U.S. Pat. No. 5,866,733, it is disclosed that 1,1-diphenylethane is prepared by reacting benzene with styrene in the presence of a synthetic zeolite catalyst, more particularly β-zeolite, in a liquid phase or in a super critical phase.
However, in the synthetic method of this kind, there are several problems in that the selectivity for an aralkylation product is often insufficient, the conditions to attain high selectivity are difficultly adopted, or a continuous long time operation is not possible.